Batch processing platform for ald and cvd

ABSTRACT

A batch processing platform used for ALD or CVD processing is configured for high throughput and minimal footprint. In one embodiment, the processing platform comprises an atmospheric transfer region, at least one batch processing chamber with a buffer chamber and staging platform, and a transfer robot disposed in the transfer region wherein the transfer robot has at least one substrate transfer arm that comprises multiple substrate handling blades. The platform may include two batch processing chambers configured with a service aisle disposed therebetween to provide necessary service access to the transfer robot and the deposition stations. In another embodiment, the processing platform comprises at least one batch processing chamber, a substrate transfer robot that is adapted to transfer substrates between a FOUP and a processing cassette, and a cassette transfer region containing a cassette handler robot. The cassette handler robot may be a linear actuator or a rotary table.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 11/426,563, filed Jun. 26, 2006, which is herein incorporatedby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to an apparatusfor processing substrates. More particularly, the invention relates to abatch processing platform for performing atomic layer deposition (ALD)and chemical vapor deposition (CVD) on substrates.

2. Description of the Related Art

The process of forming semiconductor devices is commonly conducted insubstrate processing platforms containing multiple chambers. In someinstances, the purpose of a multi-chamber processing platform or clustertool is to perform two or more processes on a substrate sequentially ina controlled environment. In other instances, however, a multiplechamber processing platform may only perform a single processing step onsubstrates; the additional chambers are intended to maximize the rate atwhich substrates are processed by the platform. In the latter case, theprocess performed on substrates is typically a batch process, wherein arelatively large number of substrates, e.g. 25 or 50, are processed in agiven chamber simultaneously. Batch processing is especially beneficialfor processes that are too time-consuming to be performed on individualsubstrates in an economically viable manner, such as for ALD processesand some chemical vapor deposition (CVD) processes.

The effectiveness of a substrate processing platform, or system, isoften quantified by cost of ownership (COO). The COO, while influencedby many factors, is largely affected by the system footprint, i.e., thetotal floor space required to operate the system in a fabrication plant,and system throughput, i.e., the number of substrates processed perhour. Footprint typically includes access areas adjacent the system thatare required for maintenance. Hence, although a substrate processingplatform may be relatively small, if it requires access from all sidesfor operation and maintenance, the system's effective footprint maystill be prohibitively large.

The semiconductor industry's tolerance for process variability continuesto decrease as the size of semiconductor devices shrink. To meet thesetighter process requirements, the industry has developed a host of newprocesses which meet the tighter process window requirements, but theseprocesses often take a longer time to complete. For example, for forminga copper diffusion barrier layer conformally onto the surface of a highaspect ratio, 65 nm or smaller interconnect feature, it may be necessaryto use an ALD process. ALD is a variant of CVD that demonstratessuperior step coverage compared to CVD. ALD is based upon atomic layerepitaxy (ALE) that was originally employed to fabricateelectroluminescent displays. ALD employs chemisorption to deposit asaturated monolayer of reactive precursor molecules on a substratesurface. This is achieved by alternating the pulsing of an appropriatereactive precursors into a deposition chamber. Each injection of areactive precursor is typically separated by an inert gas purge toprovide a new atomic layer to previous deposited layers to form auniform layer on the substrate. The cycle is repeated to form the layerto a desired thickness. The biggest drawback with ALD techniques is thatthe deposition rate is much lower than typical CVD techniques by atleast an order of magnitude. For example, some ALD processes can requirea chamber processing time from about 10 to about 200 minutes to deposita high quality layer on the surface of the substrate. While forced tochoose such processes due to device performance requirements, the costto fabricate the devices in a conventional single substrate processingchamber will increase due to the low substrate throughput. Hence, abatch processing approach is typically taken when implementing suchprocesses to make them economically viable.

Therefore, there is a need for a batch processing platform for ALD andCVD applications wherein throughput is maximized and footprint isminimized.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a batch processing platformused for ALD or CVD processing of substrates with minimized footprintand high throughput. In one embodiment, the processing platformcomprises an atmospheric transfer region, at least one batch processingchamber with a buffer chamber and staging platform, and a transfer robotdisposed in the transfer region wherein the transfer robot has at leastone substrate transfer arm that comprises multiple substrate handlingblades. The transfer robot may be adapted to transfer substrates betweena processing cassette and a staging cassette and may further be adaptedto be a two bar linkage robot. The platform may include two batchprocessing chambers configured with a service aisle disposedtherebetween to provide necessary service access to the transfer robotand the deposition stations. A fluid delivery system may be in fluidcommunication with the internal process volume of the at least one batchprocessing chamber and may be positioned in a facilities tower proximatethereto. A FOUP (Front Opening Uniform Pod) management system may bepositioned adjacent the platform.

In another embodiment the processing platform comprises at least onebatch processing chamber, a substrate transfer robot that is adapted totransfer substrates between a FOUP and a processing cassette, and acassette transfer region containing a cassette handler robot. Thecassette transfer region may be maintained at atmospheric pressure andthe cassette handler robot may be a linear actuator with vertical liftcapability or a rotary table. Alternatively, the cassette transferregion may be maintained at a pressure below atmospheric pressure andmay further comprise one or more load locks adapted to support theprocessing cassette proximate the substrate transfer robot. In thisaspect, the cassette handler robot may be a linear actuator withvertical lift capability or a rotary table with vertical liftcapability. In one configuration, the platform comprises two load locksand two batch processing chambers and the rotary table may be adapted torotatably position a cassette under each load lock and under eachdeposition chamber and to vertically transfer cassettes between thecassette transfer region and the deposition chambers and between thecassette transfer region and the load locks. A fluid delivery system maybe in fluid communication with the internal process volume of the atleast one batch processing chamber and may be positioned in a facilitiestower proximate thereto. A FOUP management system may be positionedadjacent the platform.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is a schematic plan view of a batch processing platform thatuses a multiple arm robot for substrate transfers.

FIG. 1B is a perspective view of the batch processing system of FIG. 1A.

FIG. 1C is a schematic vertical cross-sectional view of a batchprocessing system illustrating the factory interface, reactors, bufferchambers, and staging platforms.

FIG. 1D illustrates a schematic plan view of a batch processing systemconfigured with two batch processing stations, each served by atwo-cassette rotary table.

FIG. 1E is a cross-sectional side view of a batch processing station.

FIG. 1F illustrates one configuration of a robot assembly that may beused in a factory interface.

FIG. 1G illustrates a configuration of a robot hardware assemblycontaining a transfer robot that may be adapted to transfer a singlesubstrate at a time.

FIG. 1H illustrates one configuration of a robot hardware assembly thatcontains two transfer robots that are positioned in an opposingorientation to each other.

FIG. 1I illustrates a five blade robot arm.

FIG. 1J illustrates a preferred configuration of robot hardware assemblythat includes a single blade transfer robot and a multiple bladetransfer robot.

FIG. 1K illustrates the clearance region of a cartesian robot.

FIG. 1L illustrates the clearance region of a conventional robot.

FIG. 1M illustrates a cross-sectional side view of one configuration ofa two bar linkage robot.

FIG. 1N illustrates a schematic diagram of one configuration of aprecursor delivery system.

FIG. 1O is a perspective view of a batch processing system with aprecursor delivery system positioned on top of the system.

FIG. 1P is a side view of an exemplary stocker apparatus.

FIG. 1Q is a front elevation view of the stocker apparatus of FIG. 1P.

FIG. 2A is a schematic plan view of a batch processing platform.

FIG. 2B is a schematic side view of a batch processing platform.

FIG. 2C is a perspective view of a batch processing system.

FIG. 2D is a perspective view of a batch processing system.

FIG. 3A is a schematic plan view of a batch processing platform.

FIG. 3B is a schematic side view of a batch processing platform.

FIG. 4A is a schematic plan view of a batch processing platform.

FIG. 4B is a schematic side view of a batch processing platform.

FIG. 5 is a schematic plan view of a batch processing platform.

DETAILED DESCRIPTION

A batch processing platform for ALD and CVD applications is provided,wherein throughput is maximized and footprint is minimized. In oneembodiment, throughput is improved by using a multiple arm robot totransfer substrates. In another embodiment, a cassette handler robot isused to transfer entire cassettes to improve throughput.

Multiple Arm Robot Platform

In this embodiment, a robot with multiple arms transfers substratesbetween a staging cassette and a processing cassette using an armconfigured with multiple blades to reduce transfer times therebetween.Because a processing chamber is idle during substrate transfers, it isbeneficial for system throughput to minimize the time required fortransferring substrates into and out of a processing cassette. The robotalso transfers substrates between a substrate transport pod and thestaging cassette using another arm configured with a single blade toaccommodate the difference in substrate spacing between the pod and thestaging cassette. Configurations include a cartesian robot-basedplatform as well as a configuration with two batch processing chambersand a common access space therebetween that allows all components of theplatform to be accessed for maintenance without side access to theplatform.

FIG. 1A is a schematic plan view of one aspect of the invention, a batchprocessing platform using a multiple arm robot for substrate transfers,hereinafter referred to as system 100. System 100 includes one or morebatch processing stations 101A, 101B, a system controller 111, a factoryinterface (FI) 102, containing a transfer robot assembly 103 and one ormore load stations 104A-C, and a process fluid delivery system, whichmay be contained in a facilities tower 130. For illustrative purposes,transfer robot assembly 103 is illustrated in three positionssimultaneously, i.e., adjacent load stations 104A-C, adjacent reactor121A and adjacent reactor 121B. The batch processing stations 101A, 101Bare disposed adjacent FI 102 and proximate each other to minimize theoverall footprint of batch processing platform 100 and the distancenecessary for transfer robot assembly 103 to travel when transferringsubstrates between load stations 104A-C and batch processing stations101A, 101B. Two batch processing stations 101A, 101B are illustrated inFIG. 1A, however additional stations may be added easily. A facilitiestower 130 may be positioned a service distance 137 from batch processingstation 101B and FI 102 and may be connected to other components ofsystem 100 via an overhead rack 140. Service distance 137 allows accessdoor 135A to be opened for servicing transfer robot assembly 103.

Batch processing stations 101A, 101B may be configured to perform thesame batch process simultaneously on different groups of substrates, orthey may be configured to perform two different batch processessequentially on the same group of substrates. In the formerconfiguration, the starting time for substrate processing in each batchprocessing station may be staged, i.e., alternated, to minimize idletime associated with the transfer of substrates to and from batchprocessing stations 101A, 101B; transfer robot assembly 103 is onlyrequired to load and unload one batch processing station at a time. Inthe latter configuration, a group of substrates undergoes a first batchprocess in one batch processing station and then undergoes a secondbatch process in the other batch processing station. Alternatively,system 100 may be configured with a combination of batch processingstations and single-substrate processing stations. This configuration ofsystem 100 is particularly useful when an unstable batch film requiressome form of post-processing, such as a capping process, since thebatch-processed substrates may immediately undergo the desiredpost-processing.

In general operation, substrates are typically transported to system 100in FOUP's, that are positioned on the load stations 104A-C. Transferrobot assembly 103 may transfer a first batch of substrates to a stagingcassette adjacent the batch processing station while the batchprocessing station is processing a second batch of substrates in aprocessing cassette. Transfer robot assembly 103 may perform thetransfer between FOUP's and staging platforms with a robot armconfigured with a single blade. After processing, substrates may beswapped between the staging cassette and the desired processing cassetteby transfer robot assembly 103 using a robot arm configured withmultiple blades. If any single-substrate processing chambers are presenton system 100, transfer robot assembly 103 transfers substrates betweenthe single-substrate processing chambers and the appropriate stagingplatform using a robot arm configured with a single blade.

In a configuration of system 100 in which sequential batch processes areperformed on the same group of substrates, substrates may be transferredto a batch processing station from a first staging cassette prior toprocessing and then transferred to a second staging cassette afterprocessing. For example, transfer robot assembly 103 may transfer agroup of substrates from a staging cassette 123A to batch processingstation 101A for a first batch process. Upon completion of the firstbatch process, transfer robot assembly 103 transfers the group ofsubstrates from batch processing station 101A to staging cassette 123B.When batch processing station 101B is available for processing, transferrobot assembly 103 then transfers the group of substrates from stagingcassette 123B to batch processing station 101B for the second batchprocess. As noted above, a robot arm configured with multiple blades isused for transfers between staging cassettes and batch processingstations, since there is no difference in substrate spacingtherebetween.

Batch Processing Stations

FIG. 1B is a perspective view of system 100 with access panels 120A,120B and facilities tower 130 removed for clarity. Referring to FIGS. 1Aand 1B, batch processing station 101A includes a reactor 121A,containing an internal process volume 127, a buffer chamber 122Apositioned adjacent reactor 121A, and a staging platform 123A adapted tosupport a staging cassette (not shown) proximate batch processingchamber 121A. Similarly, batch processing station 101B includes areactor 121B, a buffer chamber 122B, and a staging platform 123B adaptedto support a staging cassette (not shown) proximate batch processingchamber 121 B.

FIG. 1C is a schematic vertical cross-sectional view of system 100illustrating FI 102, reactors 121A, 121B, buffer chambers 122A, 122B,and staging platforms 123A, 123B. Preferably, and as illustrated inFIGS. 1B and 1C, buffer chambers 122A, 122B are not only adjacent to,but also vertically aligned with reactors 121A, 121B, respectively,minimizing the footprint of batch system 100. In the configurationillustrated in FIGS. 1B, 1C, buffer chambers 122A, 122B are positioneddirectly below reactors 121A, 121B, respectively. Buffer chambers 122A,122B are adapted to act as vacuum load locks for the loading andunloading of a processing cassette 146 into and out of reactors 121A,121B, respectively. Buffer chambers 122A, 122B are fluidly coupled to avacuum source. The vacuum source may be a remote vacuum source or avacuum pump 171 contained inside system 100. It is important to minimizethe time required for pumping down and venting buffer chambers 122A,122B, because reactors 121A, 121B are idle during buffer chamber pumpingand venting. To that end, buffer chambers 122A, 122B are further adaptedto contain the minimum volume necessary to contain the processingcassette in order to speed the pumping and venting process. For example,for a processing cassette adapted to support circular substrates in avertically aligned column, buffer chambers 122A, 122B are preferablyconfigured as cylindrical chambers with a minimal vertical clearanceabove and below the processing cassette and with a minimal radialclearance around the processing cassette and substrates therein, asdepicted in FIG. 1B. Buffer chambers 122A, 122B both further include alift mechanism 600, transfer openings 36, 37, and vacuum-tight doors156, 157. Lift mechanism 600 may be pneumatic actuator, a stepper motor,or other vertical actuators known in the art.

In operation, processing cassette 146 is loaded with substrates W fromstaging cassette 186 via transfer robot assembly 103 while a bufferchamber (in this example, buffer chamber 122A) is vented to atmosphereand transfer opening 36 is open to transfer region 135. For clarity,only one robot arm 162, which is configured with five blades 161 isillustrated in FIG. 1C. The substrate loading/unloading process isdescribed below in conjunction with FIGS. 1F-1I. Vacuum-tight door 156is closed and buffer chamber 122A is pumped down to the same level ofvacuum present in process volume 127, generally between about 0.5 and 20Torr. Vacuum-tight door 157 is then opened and lift mechanism 600transfers processing cassette 146 into process volume 127 for ALD or CVDprocessing of substrates W. For some ALD and CVD processes, it isdesirable to pressure cycle substrates W in buffer chamber 122A, i.e.,buffer chamber 122A is alternately pumped down to process pressure andvented with a very dry gas to remove residual moisture adsorbed onto thesurfaces of substrates W and processing cassette 146. In oneconfiguration, lift mechanism 600 lowers back to buffer chamber 122A andvacuum-tight door 157 closes during processing in process volume 127.After processing is complete, lift mechanism 600 transfers processingcassette 146 back to buffer chamber 122A and vacuum-tight door 157closes, isolating process volume 127 from buffer chamber 122A. Bufferchamber 122A is then vented to atmospheric pressure and substrates W aretransferred to staging cassette 186 for cooling and subsequent removalfrom system 100.

Isolating process volume 127 from buffer chamber 122A with vacuum-tightdoor 157 while transferring substrates W to staging cassette 186 allowsprocess volume 127 to remain as close as possible to process temperatureand pressure between batches of substrates. This is beneficial toprocess repeatability and throughput since little time is required forprocess conditions in process volume 127 to stabilize to desiredconditions. Process volume 127 for batch processing chambers may berelatively large to accommodate a typical processing cassette 146, forexample, on the order of 1 m in height. Because of this, stabilizationof the pressure and temperature in process volume 127 can betime-consuming after being vented to atmospheric pressure. Hence,chamber idle time—in this case stabilization time—is reducedsignificantly by isolating process volume 127 during substrate transfersbetween processing cassette 146 and staging cassette 186. In addition,fewer contaminants are able to enter process volume 127 as a result oftransferring processing cassette 146 between buffer chamber 122A andreactor 121A.

In one configuration, lift mechanism 600 may also be adapted to assistin servicing the reactor. Referring to FIG. 1B, lift mechanism 600 maybe used to lower difficult-to-access components of reactor 121A intobuffer chamber 122A for easy removal from access panel 120A. Improvedserviceability reduces system downtime during maintenance procedures,improving COO.

Reactors 121A, 121B are adapted to perform a CVD and/or an ALD processon substrates W supported on a processing cassette 146 and containedtherein. A more detailed description of an ALD or CVD reactor that maybe contained in some configurations of the invention may be found incommonly assigned U.S. patent application Ser. No. 11/286,063, filed onNov. 22, 2005, which is hereby incorporated by reference in its entiretyto the extent not inconsistent with the claimed invention. Reactors121A, 121B are fluidly coupled to a process fluid delivery system thatis adapted to provide the necessary appropriate reactive precursor andother process fluids. Preferably, the process fluid delivery system iscontained in a facilities tower 130 and coupled to reactors 121A, 121Bvia an overhead rack 140, illustrated in FIG. 1A. Facilities tower 130is described below in conjunction with FIG. 1N. Electrical and otherfacilities, such as system controller 111 may also be located infacilities tower 130. Alternatively, the fluid delivery system may bepositioned remotely in another area of the fabrication plant and may befluidly coupled to reactors 121A, 121B via underfloor connections (notshown).

Referring to FIG. 1C, staging platforms 123A, 123B are positioned in FI102 and are each adapted to support a staging cassette 186 proximatereactors 121A, 121B, respectively. Typically, substrates are supportedin a sealable substrate transport pod, hereinafter referred to as afront-opening uniform pod (FOUP), at a lower density than during batchprocessing in an ALD or CVD chamber, i.e., there is a 10 mmsubstrate-to-substrate spacing in a FOUP vs. a 6 mm to 8 mm spacing in aprocessing cassette 146. It is important to note that a staging cassette186 supported proximate a batch processing chamber may be adapted tosupport substrates at the identical substrate density at whichsubstrates are supported in a processing cassette 146, providingsubstantial throughput and cost benefits. For example, a simple singleblade robot arm, such as that described below in conjunction with FIG.1G, may be used to transfer substrates between staging cassettes 123A,123B and load stations 104A-C. Although transferring substratestherebetween with a multiple blade robot arm is faster that with asingle blade robot arm, there is generally no throughput gain oversingle blade transfer of substrates. This is because substrate transfersbetween staging cassettes 123A, 123B and load stations 104A-C may takeplace “off-line”, i.e., while reactors 121A, 121B are processingsubstrates. Transfer times that directly affect system throughput arethose between staging platforms 123A, 123B and buffer chambers 122A,122B, as described above in conjunction with FIGS. 1A-C.

Because staging cassette 186 may be adapted to support substrates at theidentical substrate density at which substrates are supported inprocessing cassette 146, substrate transfers may be conductedtherebetween with a multiple blade, fixed pitch robot, such as thatdescribed below in conjunction with FIG. 1I. Multiple blade robotsgreatly reduce substrate transfer time since multiple substrates may betransferred at one time. System throughput may be improved significantlythereby, since shorter transfer times reduce reactor idle time.

Staging cassette 186 and processing cassette 146 may be adapted tosupport a relatively large number of substrates, i.e., more than aretypically contained in a standard FOUP. Because some processes, e.g.,ALD processes, are so time consuming, it is beneficial for COO for asmany substrates as practicable to be processed in a single batch. Hence,staging cassette 186 and processing cassette 146 are preferably adaptedto support a batch of between about 50 and about 100 substrates. Largerbatches are also possible, but the manipulation of cassettes so large ina reliable and safe manner becomes increasingly problematic. Processingcassette 146 may be constructed of any suitable high temperaturematerial such as, for instance, quartz, silicon carbide, or graphite,depending upon desired process characteristics

Staging platforms 123A, 123B may also serve as cooling platforms onwhich substrates may cool after unloading from reactors 121A, 121B.Typically, substrates unloaded from ALD and CVD chambers are too hot(i.e., >100° C.) to be loaded directly into a standard FOUP. Stagingplatforms 123A, 123B may also be adapted with a conventional robotvertical motion assembly 187, as shown in FIG. 1C. To minimize thecomplexity of system 100, it is preferred that staging platforms 123A,123B are stationary components and the vertical motion required forsubstrate hand-offs is carried out by transfer robot assembly 103.

In one configuration of system 100, a staging cassette 186 that issupported on staging platforms 123A, 123B may contain more substratesupport shelves 185 than processing cassette 146 disposed in bufferchambers 122A, 122B. This allows substrates to be swapped betweenstaging cassette 186 and processing cassette 146 without the use of athird substrate staging location and without the use of an additionaltransfer robot assembly, such as second transfer robot 86B (describedbelow in conjunction with FIG. 1H). For example, referring to FIG. 1C,processing cassette 146 has nine substrate support shelves 185 andstaging cassette 186 has nine support shelves 185 plus one or moreadditional shelves 185A. Hence, transfer robot assembly 103 may remove aprocessed substrate W from processing cassette 146 and place it in theunused additional shelf 185A. An unprocessed substrate is then removedfrom staging cassette 186 by transfer robot assembly 103 to the nowempty support shelf 185 in processing cassette 146, leaving one ofsupport shelves 185 open in staging cassette 186. The above process maythen be repeated until all substrates originally in processing cassette146 have been swapped with the substrates originally in staging cassette186. In a similar configuration, when transfer robot assembly 103includes a multi-blade robot arm (described below in conjunction withFIG. 1I) for transferring substrates between staging cassette 186 andprocessing cassette 146, it is preferred that the number of additionalshelves 185A is equal to the number of blades on the multi-blade robotarm of transfer robot assembly 103. This allows the same substrate swapprocedure described above, but with multiple substrates being swapped atone time.

In another configuration of system 100, staging cassette 186 may containmultiple additional shelves 185A for supporting dummy substrates, i.e.,non-production substrates, during batch processing. Due to thermalnon-uniformity and other factors, substrates near the top and bottom ofa processing cassette are often not processed uniformly compared to themajority of substrates in the processing cassette. The placement of oneor more dummy substrates in the top and bottom substrate support shelvesof a processing cassette may ameliorate this problem. The non-productiondummy substrates are placed in the top 1 to 5 substrate support shelves185 and the bottom 1 to 5 support shelves 185 of processing cassette146. Dummy substrates may be used for multiple batch processes, e.g.,about 5 or 10 times, before being replaced, and therefore do not need tobe removed from system 100 after each batch process is performed. Toreduce the time required to reload dummy substrates into processingcassettes, aspects of the invention contemplate the storage of dummysubstrates on additional shelves 185A contained in staging cassette 186.Hence, dummy substrates are stored in transfer region 135 in proximityto the batch processing stations 101A, 101B, whenever batch processesare not being performed therein. In addition to reducing the timerequired to load dummy substrates into a processing cassette, storage ofdummy substrates on additional shelves 185A reduces the number of FOUP'sthat need to be stored in the stocker 150 (shown in FIG. 1B anddescribed below in conjunction with FIGS. 1P and 1Q).

In one configuration, staging platforms 123A, 123B are each adapted toserve as a two-cassette rotary table for rotatably swapping a firstprocessing cassette of unprocessed substrates with a second processingcassette processed substrates. FIG. 1D illustrates a schematic plan viewof system 100 configured with two batch processing stations 101A, 101B,each served by a two-cassette rotary table 129A, 129B, respectively. Inthis configuration, staging cassette 186 acts as the second processingcassette.

While a batch of substrates in processing cassette 146 are beingprocessed in the reactor 121A of batch processing station 101A, stagingcassette 186 is being loaded with substrates from load stations 104A-C.After processing is complete in reactor 121A, processing cassette 146 islowered onto rotary table 129A by a lift mechanism (not shown forclarity). Rotary table 129A then rotates 180°, swapping the locations ofprocessing cassette 146 and staging cassette 186. The processedsubstrates cool in transfer region 135 and are then transferred to oneor more FOUP's positioned on load stations 104A-C. Simultaneously, thelift mechanism transfers staging cassette 186 into reactor 121A forprocessing. Hence, no significant length of time is required to transfersubstrates from transfer region 135 to reactor 121A. Rather thantransferring individual substrates between a staging cassette and aprocessing cassette, in this configuration of system 100 the staging andprocessing cassettes are simply swapped by rotary table 129A. In oneexample, the batch processing stations 101A, 101B each include a bufferchamber for isolating reactors 121A, 121B as described above inconjunction with FIG. 1D.

In another configuration, rotary tables 129A, 129B are each contained ina buffer chamber 128, as illustrated in FIG. 1E. FIG. 1E is across-sectional side view of a batch processing station 101A whichincludes a reactor 121A containing a processing cassette 146A and abuffer chamber 128 containing a two-cassette rotary table 129A and asecond processing cassette 146B. A lift mechanism 600A, in this case avertical indexer robot, transfers cassettes between rotary table 129Aand reactor 121A. During processing of processing cassette 146A, bufferchamber 128 is vented to atmospheric pressure and a vacuum-tight door156 opens to provide access to second processing cassette 146B fromtransfer robot assembly 103. After second processing cassette 146B isloaded with substrates, vacuum-tight door 156 is closed and bufferchamber 128 is vented or pressure cycled in preparation for swappingsecond processing cassette 146B with processing cassette 146A. Thisconfiguration allows the speedy reloading of reactor 121A with aprocessing cassette, minimizing reactor downtime. All pump-down andventing of buffer chamber 128 take place while substrates are beingprocessed in reactor 121A.

Factory Interface

Referring back to FIG. 1C, the factory interface (FI) 102, contains atransfer robot assembly 103, a transfer region 135, an environmentalcontrol assembly 110 and one or more load stations 104A-C (shown in FIG.1A). FI 102 maintains transfer region 135 as a clean mini-environment,i.e., a localized, atmospheric pressure, low-contaminant environment,via a fan-powered air filtration unit. FI 102 is intended to provide aclean environment, i.e., transfer region 135, in which a substrate maybe transferred between a FOUP positioned on any of load stations 104A-Cand reactors 121A, 121B. Recently processed substrates are also able tocool after processing in the low-contamination environment of transferregion 135 prior to being transferred out of system 100 and into a FOUP.

FIG. 1C is a schematic vertical cross-sectional view of system 100illustrating FI 102, reactors 121A, 121B, buffer chambers 122A, 122B,and staging platforms 123A, 123B. For clarity, load stations 104A-C arenot shown. In one aspect, environmental control assembly 110 contains afiltration unit 190 that may contain a filter 191, such as a HEPAfilter, and a fan unit 192. The fan unit 192 is adapted to push airthrough the filter 191, through transfer region 135, and out the base193A of the FI 102. FI 102 includes walls 193 to enclose transfer region135 to better provide a controlled environment to perform the substrateprocessing steps. Generally the environmental control assembly 110 isadapted to control the air flow rate, flow regime (e.g., laminar orturbulent flow) and particulate contamination levels in the transferregion 135. In one aspect, the environmental control assembly 110 mayalso control the air temperature, relative humidity, the amount ofstatic charge in the air and other typical processing parameters thatcan be controlled by use of conventional clean room compatible heating,ventilation, and air conditioning (HVAC) systems known in the art.

Load stations 104A-C are adapted to support, open, and close a FOUP orother sealable substrate transport pod placed thereon. Hence, loadstations 104A-C fluidly couple substrates contained in a loadstation-supported FOUP to transfer region 135 without exposing thesubstrates to contaminants that may be present outside the FOUP and/ortransfer region 135. This allows substrates to be removed, replaced, andresealed in a FOUP in a clean and fully automated manner.

Cartesian Robot

FIG. 1F illustrates one configuration of a robot assembly 11 that may beused as transfer robot assembly 103 in FI 102. The robot assembly 11generally contains a robot hardware assembly 85, a vertical robotassembly 95 and a horizontal robot assembly 90. A substrate can thus bepositioned in any desired x, y and z position in the transfer region 135by the cooperative motion of the robot hardware assemblies 85, verticalrobot assembly 95 and horizontal robot assembly 90, from commands sentby the system controller 111.

The robot hardware assembly 85 generally contains one or more transferrobots 86 that are adapted to retain, transfer and position one or moresubstrates by use of commands sent from the system controller 111. Inthe configuration depicted in FIG. 1F, two transfer robots 86 areincluded in robot hardware assembly 85. In a preferred configuration,the transfer robots 86 are adapted to transfer substrates in ahorizontal plane, such as a plane that includes the X and Y directionsillustrated in FIGS. 1A and 1F, due to the motion of the varioustransfer robot 86 components. Hence, the transfer robots 86 are adaptedto transfer a substrate in a plane that is generally parallel to thesubstrate supporting surface 87C (see FIG. 1M) of robot blade 87. Theoperation of one configuration of transfer robots 86 is described belowin conjunction with FIG. 1M.

FIG. 1G illustrates a configuration of robot hardware assembly 85containing a transfer robot 86 that may be adapted to transfer a singlesubstrate W at a time. A single substrate transfer capability fortransfer robot assembly 103 is beneficial to system 100 because itallows the transfer of substrates between a FOUP disposed on one of loadstations 104A-C and staging platforms 123A, 123B despite the differencein substrate density generally present between a standard FOUP andstaging platforms 123A, 123B. Multiple blade transfer of substratestherebetween necessitates a variable pitch robot blade, i.e., a multipleblade robot arm with the capability to vary the distance, or pitch,between substrates. Variable pitch robot blades, while known in the art,are relatively complex, which may impact overall system downtime andtherefore COO.

FIG. 1H illustrates one configuration of robot hardware assembly 85 thatcontains two transfer robots 86A, 86B that are positioned in an opposingorientation to each other, i.e., vertically mirrored, so that the blades87A-B (and first linkages 310A-310B) can be placed a small distanceapart. The configuration shown in FIG. 1H, i.e., an “over/under” typeblade configuration, may be advantageous, for example, where it isdesired to “swap” substrates, i.e., to remove a substrate from alocation and immediately replace it with another substrate with minimalrobot motions. For example, it is desirable to remove a processedsubstrate from processing cassette 146 with transfer robot 86A andimmediately replace it with an unprocessed substrate that has alreadybeen taken from staging cassette 186 and is available on second transferrobot 86B. Because there is no need to transfer the processed substrateto another location before loading the unprocessed substrate, thissubstrate swap can take place without necessitating robot hardwareassembly 85 or robot assembly 11 leaving their basic positions,substantially improving system throughput. This is particularly the casefor system 100 during transfer of substrates between staging platforms123A, 123B and buffer chambers 122A, 122B, respectively. The over/underblade configuration illustrated in FIG. 1H allows unprocessed substratesdisposed on staging platforms 123A, 123B to be swapped with processedsubstrates disposed in buffer chambers 122A, 122B respectively. Hence,no additional staging/cooling location for substrates is required toenable this substrate swap when the over/under blade configuration, orvariations thereof, is used. This significantly reduces the footprint ofsystem 100 while minimizing the time reactors 121A, 121B are idle whileprocessing cassette 146 is being emptied and refilled with substrates.

In another configuration, robot hardware assembly 85 may further includeat least one multiple blade, fixed-pitch robot arm, enabling swapping ofmultiple substrates between staging platforms 123A, 123B and bufferchambers 122A, 122B as described above. In one example, transfer robot86A includes a five blade robot arm 87H, as illustrated in FIG. 1I. Inanother example, transfer robot 86A and second transfer robot 86B bothinclude a multiple blade robot arm, enabling swapping of multiplesubstrates between staging platforms 123A, 123B and buffer chambers122A, 122B, respectively, as described above in conjunction with FIG.1H.

FIG. 1J illustrates a preferred configuration of robot hardware assembly85 of robot assembly 11, which includes a single blade transfer robot86C and a multiple blade transfer robot 86D. Single blade transfer robot86C may transfer substrates W between load stations 104A-C and stagingcassette 186. Multiple blade transfer robot 86D may transfer substratesW between staging cassette 186 and processing cassette 146.

It is important to note that the configuration of system 100, asillustrated in FIG. 1A, allows the transfer of substrates betweenstaging platforms 123A, 123B and buffer chambers 122A, 122B,respectively, without the need for horizontal translation of verticalrobot assembly 95 by horizontal robot assembly 90, which substantiallyreduces transfer times. This configuration significantly increasessystem throughput by minimizing processing chamber idle time. Becausereactors 121A, 121B are idle whenever their respective processingcassette 146 is being unloaded, the substrate transfer should be carriedout as quickly as possible. Eliminating the need for horizontaltranslation of vertical robot assembly 95 during substrate transferaccomplishes this goal.

An additional advantage of the use of a cartesian robot, as illustratedin FIGS. 1F-1J, is that a smaller system footprint is required forsubstrate transfers to be carried out within transfer region 135compared to conventional substrate transfer robots, such as a selectivecompliance assembly robot arm (SCARA). This is illustrated by FIGS. 1Kand 1L. The width W₁, W₂ of a clearance region 90A that surrounds atransfer robot assembly 103 is minimized. Clearance region 90A isdefined as a region adjacent a substrate transferring robot, such astransfer robot assembly 103, wherein the substrate transferring robot'scomponents and a substrate S are free to move without colliding withother cluster tool components external to the substrate transferringrobot. While the clearance region 90A may be described as a volume,often the most important aspect of the clearance region 90A is thehorizontal area (x and y-directions), or footprint, occupied by theclearance region 90A, which directly affects a cluster tool's footprintand COO. The footprint of clearance region 90A is illustrated in FIGS.1K, 1L as the regions defined by the length L and width W₁, W₂,respectively. In addition to smaller system footprint, a smallerclearance region allows closer positioning between transfer robotassembly 103 and locations that are accessed thereby, such as bufferchambers 122A, 122B and staging platforms 123A, 123B, reducing substratetransfer times and increasing throughput. The configurations of transferrobot assembly 103 described herein have particular advantage over aSCARA robot CR illustrated in FIG. 1L. This is due to the way in whichthe transfer robot 86, as illustrated in FIG. 1K, may retract itscomponents to be oriented along the major length L of clearance region90A. A SCARA robot CR, as illustrated in FIG. 1L, cannot.

FIGS. 1G, 1H, 1I and 1M illustrate one configuration of a two barlinkage robot 305 that, when used as transfer robot 86, may retract asshown in FIG. 1K. Referring to FIG. 1M, Two bar linkage robot 305generally contains a support plate 321, a first linkage 310, a robotblade 87, a transmission system 312, an enclosure 313 and a motor 320.In this configuration the two bar linkage robot 305, which is serving astransfer robot 86, is attached to the vertical motion assembly 95through the support plate 321 which is attached to the vertical motionassembly 95 (shown in FIG. 1F). FIG. 1M illustrates a cross-sectionalside view of one configuration of the two bar linkage robot 305 type oftransfer robot assembly 86. The transmission system 312 in the two barlinkage robot 305 generally contains one or more power transmittingelements that are adapted to cause the movement of the robot blade 87 bymotion of the power transmitting elements, such as by the rotation ofmotor 320. In general, the transmission system 312 may contain gears,pulleys, etc. that are adapted to transfer rotational or translationmotion from one element to another. In one aspect the transmissionsystem 312, as shown in FIG. 1M, contains a first pulley system 355 anda second pulley system 361. The first pulley system 355 has a firstpulley 358 that is attached to the motor 320, a second pulley 356attached to the first linkage 310, and a belt 359 that connects thefirst pulley 358 to the second pulley 356, so that the motor 320 candrive the first linkage 310. In one aspect, a plurality of bearings 356Aare adapted to allow the second pulley 356 to rotate about the axis V₁of the third pulley 354.

The second pulley system 361 has a third pulley 354 that is attached tosupport plate 321, a fourth pulley 352 that is attached to the blade 87and a belt 362 that connects the third pulley 354 to the fourth pulley352 so that the rotation of the first linkage 310 causes the blade 87 torotate about the bearing axis 353 (pivot V₂) coupled to the firstlinkage 310. When in transferring a substrate the motor drives the firstpulley 358 which causes the second pulley 356 and first linkage 310 torotate, which causes the fourth pulley 352 to rotate due to the angularrotation of the first linkage 310 and belt 362 about the stationarythird pulley 354. In one embodiment, the motor 320 and system controller111 are adapted to form a closed-loop control system that allows theangular position of the motor 320 and all the components attachedthereto to be controlled. In one aspect the motor 320 is a stepper motoror DC servomotor.

A more detailed description of a cartesian robot that may be containedin some configurations of the invention may be found in commonlyassigned U.S. patent application Ser. No. 11/398,218 filed on Apr. 5,2006, which is hereby incorporated by reference in its entirety to theextent not inconsistent with the claimed invention.

Process Fluid Delivery System

For ALD and CVD processing of substrates, there are generally threemethods that chemical precursors are treated to form a process fluidthat can be delivered to a process volume of a processing chamber todeposit a layer of a desired material on a substrate. The term processfluid, as used herein, is generally meant to include a gas, vapor, or aliquid. The first treatment method is a sublimation process in which theprecursor, which is in solid form in an ampoule, is vaporized using acontrolled process, allowing the precursor to change state from a solidto a gas or vapor in the ampoule. The precursor-containing gas or vaporis then delivered to the process volume of a processing chamber. Thesecond method used to generate a precursor-containing process gas is byan evaporation process, in which a carrier gas is bubbled through atemperature controlled liquid precursor, and thus is carried away withthe flowing carrier gas. A third process used to generate a precursor isa liquid delivery system in which a liquid precursor is delivered to avaporizer by use of a pump, in which the liquid precursor changes statefrom a liquid to a gas by the addition of energy transferred from thevaporizer. The added energy is typically in the form of heat added tothe liquid. In any of the three methods described above for creating aprecursor-containing process fluid, it is typically necessary to controlthe temperature of the precursor ampoule as well as the fluid deliverylines between the ampoule and the processing chamber. This isparticularly true of ALD processes, wherein temperature control of saiddelivery lines is very important in achieving process repeatability.Hence, when tight control of precursor temperature is required, thedistance between the precursor ampoule and the processing chamber servedthereby should be minimized to avoid unnecessary system cost,complexity, and reliability.

FIG. 1N illustrates a schematic diagram of one configuration of aprecursor delivery system 501 that is used to deliver a process fluid tothe process volume of a processing chamber, such as reactor 121A. In theexample illustrated, precursor delivery system 501 is a liquid deliverytype process fluid source. The components of precursor delivery system501 may be contained proximate each other in a facilities tower 130,which is illustrated in FIG. 1A. Precursor delivery system 501 isfluidly coupled to reactor 121A via inlet line 505, which may becontained in an overhead rack 140. The routing of inlet line 505 toreactor 121A through overhead rack 140 enables positioning of precursordelivery system 501 proximate reactors 121A without impeding serviceaccess to batch processing stations 101A, 101B. Ordinarily, precursordelivery system 501 is located significantly further from reactor 121A,for example in a different room or even a different floor. Referringback to FIG. 1N, precursor delivery system 501, in this configuration,generally includes the following components: an ampoule gas source 512,an ampoule 139 containing a precursor “A”, a metering pump 525, avaporizer 530, an isolation valve 535, a collection vessel assembly 540and a final valve 503. The collection vessel assembly 540 generallyincludes the following components: an inlet 546, an outlet 548, a vessel543, a resistive heating element 541 surrounding the vessel 543, aheater controller 542 and a sensor 544. In one configuration, the heatercontroller 542 is part of the system controller 111.

Precursor delivery system 501 is adapted to deliver a process gas to theprocess volume 127 of reactor 121A from the ampoule 139 containing aliquid precursor. To form a gas from a liquid precursor, the liquidprecursor is vaporized by use of a metering pump 525 which pumps theprecursor into the vaporizer 530, which adds energy to the liquid,causing it to change state from a liquid to a gas. Metering pump 525 isadapted to control and deliver the liquid precursor at a desired flowrate set point throughout the process recipe step, by use of commandsfrom the system controller 111. The vaporized precursor is thendelivered to the collection vessel assembly 540 where it is stored untilit is injected into the process volume 127 and across the surface of thesubstrates W.

The inlet line 505 is heated to assure that an injected precursor doesnot condense and remain on the surface of inlet line 505, which cangenerate particles and affect the chamber process. It is also common tocontrol the temperature of the inlet line 505 and other components ofprecursor delivery system 501 below the precursor decompositiontemperature to prevent gas phase decomposition and/or surfacedecomposition of the precursor thereon. Hence, reliable temperaturecontrol of numerous components of precursor delivery system 501,including inlet line 505, is important to CVD and particularly ALDprocesses. The temperature control should reliably maintain thenecessary components of precursor delivery system 501 within awell-defined temperature window to avoid serious process problems.

Because reliable and accurate temperature control of inlet line 505 aremade much more problematic and expensive for a longer inlet line 505,inlet line 505 may be minimized by positioning precursor delivery system501 as close as possible to the reactors serviced thereby. Referring toFIG. 1A, precursor delivery system 501 may be located in facilitiestower 130, which is proximate reactors 121A, 121B. To that end,facilities tower 130 is positioned as close as possible to reactors121A, 121B while still maintaining a service distance 137 that isadequate to accommodate service of facilities tower 130 and othercomponents of system 100, such as batch processing station 101B andtransfer robot assembly 103 via access door 135A. Service distance 137may be a SEMI (Semiconductor Equipment and Materials International)compliant service distance, usually on the order of 36 inches.Alternatively, precursor delivery system 501 may be positioned incabinets 146A, 146B proximate batch processing stations 101A, 101B,respectively, as shown in FIG. 1B. In another configuration, precursordelivery system 501 may be positioned on top of system 100 in cabinets145, as illustrated in FIG. 1O.

FOUP Stocker

Unlike single-substrate processing systems, a batch processing system,such as system 100, typically processes substrates from multiple FOUP'ssimultaneously. For example, a standard FOUP contains up to 25substrates whereas a batch of substrates processed by system 100 may beas large as 50 or 100 substrates. Considering that system 100 mayinclude two or more batch processing stations, as many as 100 to 200substrates may be undergoing processing at any one time in system 100,the equivalent of up to 12 or more FOUP's. In order to minimize thefootprint of system 100, however, FI 102 typically only includes two orthree load stations 104A-C, as illustrated in FIG. 1A. Empty FOUP'swaiting for processed substrates must therefore be removed from the loadstations 104A-C to allow loading and unloading of substrates from otherFOUP's. In addition, each FOUP must be correctly staged to load stations104A-C after processing so that the correct substrates are loadedtherein. Further, FOUP's must be received from and returned to thecentral FOUP transport system of the fabrication plant, such as anoverhead monorail FOUP transport system. Hence, managing a large numberof FOUP's during processing without slowing throughput or unreasonablyexpanding the footprint of system 100 is a non-trivial consideration.

To that end, system 100 may be configured with a FOUP stocker 150 (shownin FIG. 1B) positioned proximate load stations 104A-C. The FOUP stockermay include one or more storage shelves and FOUP transfer mechanismsthat may include a shelf capable of raising or lowering a FOUP betweenthe FOUP storage locations and load stations 104A-C of system 100. Inone configuration, the storage shelves are themselves adapted to raiseand lower a FOUP therebetween. In another configuration, a FOUP handleror other FOUP transfer device may be adapted to transfer a FOUP betweenthe FOUP storage locations and load stations 104A-C. The FOUP stockermay be positioned in front of or beside the fabrication tool, but toavoid increasing the footprint of system 100, the FOUP stocker ispreferably positioned over load stations 104A-C.

FIG. 1P is a side view of a stocker apparatus, stocker 150, adapted forthe management of sealed substrate transport pods, such as FOUP's,during the processing by a batch processing platform, such as system100. The stocker 150 includes first and second vertical transfermechanisms, i.e., a first robot 713 and a second robot 715,respectively. The first robot 713 includes a first y-axis component 717and a first x-axis component 719 movably coupled to the first y-axiscomponent 717 such that the first x-axis component 719 may travel alongthe length of the first y-axis component 717. Similarly, the secondrobot 715 includes a second y-axis component 721 and a second x-axiscomponent 723 movably coupled to the second y-axis component 721 suchthat the second x-axis component 723 may travel along the length of thesecond y-axis component 721. Operatively coupled between the first robot713 and the second robot 715 are one or more storage locations 725 a,725 b.

The first robot 713 is configured such that when the first x-axiscomponent 719 is at the lower portion of the first y-axis component 717it may access the one or more load stations 104A-B and position a FOUPthereon. The first robot 713 is further configured such that when thefirst x-axis component 719 is at the upper portion of the first y-axiscomponent 717 it may access an overhead wafer carrier transport systemsuch as a monorail, referenced generally by the numeral 729 a. Thesecond robot 715 is configured such that when the second x-axiscomponent 723 is at the lower portion of the second y-axis component 721it may also access the one or more load stations 104A-B and position aFOUP thereon. Both the first x-axis component 719 and the second x-axiscomponent 23 are configured so as to reach any of the storage locations725 a, 725 b. In a preferred configuration, first robot 713 is adaptedwith a plurality of first y-axis components 717 in lieu of storagelocations 725 a, 725 b. In this preferred configuration, second robot715 is similarly configured.

FIG. 1Q is a front elevation view of the stocker 150 of FIG. 1P whichshows a preferred arrangement of four storage locations 725 a, 725 b,725 c, and 725 d, above load stations 104A, 104B. FOUP's 751, 753, 755,and 757 are in storage on the storage locations 725 a, 725 b, 725 c and725 d, respectively. The FOUP capacity of the stocker 150 may beincreased with additional storage locations added above and/or adjacentstorage locations 725 a, 725 b, 725 c and 725 d. Additional storagelocations positioned adjacent storage locations 725 a, 725 b, 725 c and725 d may require one or more additional robots similar to first robot713 and second robot 715, each configured with an x-axis component and ay-axis component.

Multiple Arm Robot Platform—Zero Side Access Configuration

In one aspect of the invention, the multiple arm robot platform includestwo batch processing chambers configured with a service aisle disposedtherebetween to provide necessary service access to the transfer robotand the deposition stations. Required service areas are generallyincluded as part of the footprint in the COO calculation for a substrateprocessing system, often making up a substantial fraction of the overallfootprint of the system. Further, if required access areas are not onlyreduced but are eliminated on both sides of a processing system, oneprocessing system may be situated abutting other systems, maximizingefficient use of floor space. Therefore, incorporation of all requiredservice areas into other regions of a substrate processing system in amanner that eliminates the need for side access can substantially reducethe effective footprint thereof.

FIG. 2A is a schematic plan view of one aspect of the invention, a batchprocessing platform, hereinafter referred to as system 200, wherein noside access is required in order to service all components thereof. FIG.2B is a schematic side view of system 200. FIG. 2C is a perspective viewthereof.

System 200 generally includes two or more batch processing stations201A, 201B, a system controller 111, a factory interface (FI) 102,containing a transfer robot 220 and one or more load stations 104A,104B, and a process fluid delivery system. The fluid delivery system maybe contained in facilities towers 130A, 130B and is organizedsubstantially the same as the process fluid delivery system for system100, described above in conjunction with FIG. 1N. As with system 100, aFOUP stocker (not shown) may be positioned over load stations 104A, 104Bto provide local storage of FOUP's or other substrate transport podsduring batch processing of substrates.

The batch processing stations 201A, 201B are disposed adjacent FI 102and are separated from each other by a common access space 250, which isadapted to provide service access to batch processing stations 201A, 201B and to transfer robot 220. The presence of common access space 250obviates the need for side access areas along sides 251, 252 of system200, allowing system 200 to be positioned directly in contact with awall or other processing system along sides 251, 252.

Referring to FIGS. 2A-D, batch processing station 201A includes areactor 221A, a buffer chamber 222A positioned adjacent reactor 221A,and a staging platform 223A positioned in FI 102 and adapted to supporta staging cassette (not shown) proximate reactor 221A. Similarly, batchprocessing station 201B includes a reactor 221B, a buffer chamber 222B,and a staging platform 223B positioned in FI 102 and adapted to supporta staging cassette (not shown) proximate reactor 221B. Batch processingstations 201A, 201B, FI 102, and overhead tack 210 are generallyorganized the same as their counterparts in system 100, batch processingstations 101A, 101B described above in conjunction with FIG. 1A.

One difference between the organization and operation of system 200 fromsystem 100 is the relative orientation of FI 102, batch processingstations 201A, 201B, and the transfer robot. In system 200, there ispreferably one load station positioned opposite each batch processingstation. In the configuration illustrated in FIG. 2A for example, loadstations 104A, 104B are positioned opposite batch processing stations201A, 201B, respectively. Another difference between system 100 andsystem 200 is the configuration of the transfer robot. In system 200,transfer robot 220 is preferably not a cartesian robot, unlike transferrobot assembly 103. Transfer robot 220 may be a conventional SCARA robotmounted on a track 220T. Transfer robot 220 is adapted to travel alongtrack 220T to serve all batch processing stations 201A, 201B of system200. Because less service access is required for this configuration ofrobot, it may be serviced adequately from common access space 250 orfrom front skin 253.

Other features of transfer robot 220 are substantially the same astransfer robot assembly 103, including the use of a single blade robotarm for transferring substrates from the a low density FOUP to a higherdensity staging cassette and the use of a multiple blade robot arm fortransferring multiple substrates from a staging FOUP to an equal densityprocessing cassette.

In one configuration, a stationary transfer robot, i.e., nottrack-mounted, is disposed between each batch processing station 201A,201B and load station 104A, 104B, respectively. In this configuration,each transfer robot serves a single batch processing station. If batchprocessing stations 201A, 201B are each adapted to perform a differentprocess on groups of substrates sequentially, stocker 150 enables thetransfer of substrates between batch processing stations 201A, 201B bymoving FOUP's between load stations 104A, 104B as required.

System 200 may include a dedicated facilities tower 130A, 130B for eachbatch processing station 201A, 201B, as illustrated in FIGS. 2A and 2D,each containing a precursor delivery system 501. In this configuration,the use of facilities towers 130A, 130B creates an access opening 130Cbetween facilities towers 130A and 130B. In another configuration,facilities towers 130A, 130B may be combined into a single facilitiestower containing a precursor delivery system 501 for each batchprocessing station 201A, 201B.

Cassette Handler Platform

In another embodiment of the invention, a cassette handler transfers theprocessing cassette between a processing chamber and a cooling stationto minimize chamber idle time. A single arm robot transfers individualsubstrates between a substrate transport pod and a processing cassette.In one aspect, the cassette handler is a linear translator adapted totransfer a processing cassette between one or more processing chambersand a cooling station. In another aspect, the cassette handler is arotary table adapted to swap a cassette of unprocessed substrates with acassette of processed substrates.

Linear Translator Configuration

FIG. 3A is a schematic plan view of one aspect of the invention, a batchprocessing platform containing a linear translator, hereinafter referredto as system 300. The linear translator robot is adapted to transferprocessing cassettes between a staging platform, at least one batchprocessing chamber, and a cassette loading station. FIG. 3B is aschematic side view of system 300.

To maintain high throughput for a batch processing platform, it isimportant to minimize reactor idle time. Contributing factors to reactoridle time include long pump-down and vent times for the reactor,substrate cooling time, and substrate transfer time. The configurationillustrated in FIGS. 3A, 3B may reduce or eliminate the contribution ofeach of these factors on system throughput.

System 300 includes one or more reactors 1301, 1302, a cassette transferregion 1305, a factory interface (FI) 102, and a process fluid deliverysystem. FI 102 contains one or more load stations 104A-C, a cassetteloading station 1303, an environmental control assembly 110, and aloading robot 1304 adapted to transfer substrates between the loadstations 104A-C and a processing cassette positioned on cassette loadingstation 1303. Cassette transfer region 1305 contains a staging platform1306 and a linear translator robot 1320, which is mounted to ahorizontal rail 1321 and is adapted to transfer processing cassettesbetween the staging platform 1306, the reactors 1301, 1302, and thecassette loading station 1303. The process fluid delivery system may becontained in facilities towers 130A, 130B and is organized substantiallythe same as the process fluid delivery system for system 100, describedabove in conjunction with FIG. 1N. As with system 100, a FOUP stockermay be positioned over load stations 104A-C to provide local storage ofFOUP's or other substrate transport pods during batch processing ofsubstrates.

Components of system 300 that are substantially the same in organizationand operation as the corresponding components of system 200 include FI102, transfer robot 1304, reactors 1301, 1302, facilities towers 130A,130B, and the process fluid delivery system.

In operation, a first processing cassette 1330 disposed in FI 102 andpositioned on cassette loading station 1303 is loaded with substratesfrom one or more FOUP's positioned on load stations 104A-C by transferrobot 1304. In one configuration, transfer robot 1304 may be a singletrack-mounted robot similar to transfer robot 220, described above inconjunction with FIGS. 2A-C. First processing cassette 1330 is thenvertically translated to a position adjacent load lock 1309 by avertical lift mechanism 1303A, such as a vertical indexer or a motorizedlift. Processing cassette 1330 is then loaded into load lock 1309 and ispumped down to a level of vacuum substantially equal to that present incassette transfer region 1305 and reactors 1301, 1302. Processingcassette 1330 may also be pressure cycled prior to entry into cassettetransfer region 1305. After pump-down, vacuum-tight door 1312 opens andprocessing cassette 1330 is transferred from load lock 309 into cassettetransfer region 1305 by linear translator robot 1320, which is adaptedwith a cassette lift mechanism. Linear translator robot 1320 is adaptedto translate a processing cassette along horizontal path 1322, totransfer a processing cassette vertically into and out of the one ormore reactors 1301, 1302 along vertical paths 1323, and to transfer aprocessing cassette on or off of staging platform 1306. First processingcassette 1330 is then loaded into an idle reactor, such as reactor 1301or 1302 by linear translator robot 1320. After processing is complete,first processing cassette 1330 is unloaded from reactor 1301 by lineartranslator robot 1320 and transferred to staging cassette 1306 forcooling. After the substrates are sufficiently cooled, first processingcassette 1330 is transferred to load lock 1309 by linear translatorrobot 1320, vented to atmospheric pressure, lowered into FI 102 byvertical lift mechanism 1303A, and unloaded by transfer robot 1304.Alternatively, first processing cassette may undergo atmospheric coolingin load lock 1309 after being vented to atmosphere. In thisconfiguration, free or forced convective cooling may be used.

In a preferred sequence, first processing cassette 1330 is positioned inload lock 1309 with unprocessed substrates before processing iscompleted on second processing cassette 1331 in reactor 1301. In sodoing, reactor 1301 is idle for a short time, i.e., on the order ofabout 1 minute. Reactor idle time is no longer than the time necessaryfor linear translator robot 1320 to transfer second processing cassette1331 to staging platform 1306 plus the time to transfer first processingcassette 1330 into reactor 1301. Substrate loading and unloading as wellas load lock pumping and venting are carried out “off-line”, i.e., whilethe reactors are processing substrates. Hence, the reactors are not idlewhile the time-consuming steps involved in transferring substrates fromload stations 104A-C to reactors 1301, 1302 take place, maximizingsystem throughput. Preferably, reactors 1301, 1302 are staged, i.e.,substrate processing is started alternately in each, to ensure thatreactor loading/unloading is not limited by the availability of lineartranslator robot 1320.

In an alternate configuration, cassette transfer region 1305 is anatmospheric pressure transfer region, preferably purged with lowmoisture, inert gas, such as dry nitrogen. In this configuration, aprocessing cassette is loaded with substrates in FI 102 and transferreddirectly to reactors 1301, 1302 without passing through a vacuum loadlock. In this configuration, vertical lift mechanism 1303A and load lock1309 are not needed.

In another alternate configuration, each of reactors 1301, 1302 ofsystem 300 may be adapted to sequentially perform a different batchprocess on the same group of substrates. In this configuration, thepreferred processing sequence includes processing first processingcassette 1330 in reactor 1301 with the first batch process, transferringfirst processing cassette 1330 to reactor 1302 with linear translatorrobot 1320 for processing with a second batch process. First processingcassette 1330 is then transferred to staging platform 1306 for coolingand subsequent removal from systems 300 as described above.

Rotational Cross Configuration

FIG. 4A is a schematic plan view of one aspect of the invention, a batchprocessing platform, hereinafter referred to as system 400, wherein arotational cross robot is adapted to rotatably swap two pairs ofprocessing cassettes between two reactors and two vacuum load locks.FIG. 4B is a schematic side view of system 400.

As noted above, system throughput is substantially improved byperforming the most time-consuming elements of substrate transfer whilethe reactors are processing substrates, such as substrate loading andunloading and load lock pumping and venting. The configurationillustrated in FIGS. 4A and 4B may reduce or eliminate the contributionof these factors on system throughput.

System 400 includes two reactors 401, 402, two vacuum load locks 403,404, an evacuated cassette transfer region 406 positioned beneath thevacuum load locks 403, 404 and the reactors 401, 402, a factoryinterface (FI) 102, and a process fluid delivery system. Load locks 403,404 may serve as cool-down stations for cassettes containing processedsubstrates and may further serve as loading stations for transferringsubstrates between processing cassettes disposed therein and loadstations 104A-C. FI 102 contains one or more load stations 104A-C, anenvironmental control assembly 110, and a transfer robot 405 adapted totransfer substrates between the load stations 104A-C and the vacuum loadlocks 403, 404. Transfer robot 405 is substantially the same singletrack-mounted robot as transfer robot 220, described above inconjunction with FIGS. 2A-D, but with an extended z-motion capability.System 400 also includes a rotational cross robot 407 is positioned inevacuated cassette transfer region 406. Rotational cross robot 407 isadapted to position cassettes in and remove cassettes from reactors 401,402 and vacuum load locks 403, 404 by vertical motion along verticalpath 407A. Rotational cross robot 407 is further adapted to rotatablyswap two processing cassettes containing processed substrates with twoprocessing cassettes containing unprocessed substrates.

Components of system 400 that are substantially the same in organizationand operation as the corresponding components of system 200 include FI102, transfer robot 405, reactors 401,402, facilities towers 130A, 130B,overhead rack 140, and the process fluid delivery system. As with system100, a FOUP stocker may be positioned over load stations 104A-C toprovide local storage of FOUP's or other substrate transport pods duringbatch processing of substrates.

In operation, processing cassettes located in loadlocks 403, 404 areloaded with substrates from load stations 104A-C with transfer robot405. Vacuum-tight door 156 closes and loadlocks 403, 404 are evacuatedto the same level of vacuum present in evacuated transfer region 406.Gate valve 420 opens and the processing cassettes are lowered intoevacuated transfer region 406 by rotational cross robot 407. Rotationalcross robot 407 then rotates 180°, positioning the processing cassettesunder reactors 401, 402. Gate valve 421 opens and rotational cross robot407 loads the processing cassettes into reactors 401, 402, gate valve421 closes, and ALD or CVD processing may be performed on the substratescontained in the processing cassettes. After processing in reactors 401,402 is complete, rotational cross robot 407 returns the processingcassettes to load locks 403, 404 by a similar process of lowering,rotating, and lifting. Load locks 403, 404 are vented to atmosphericpressure and, once sufficiently cooled, are transferred to one or moreFOUP's positioned on load stations 104A-C.

In a preferred sequence, two processing cassettes are processed inreactors 401, 402 at the same time that two processing cassettes in loadlocks 403, 404 are being loaded with unprocessed substrates. In thisway, cassettes containing unprocessed substrates are loaded and pumpeddown while the reactors are processing two other cassettes. In addition,cassettes containing freshly processed substrates are vented toatmosphere, cooled, and unloaded while the reactors are processing othercassettes. Hence, reactor idle time is reduced to a few seconds, i.e.,the time necessary for the rotational cross robot 407 to lower, rotateand raise the processing cassettes.

Atmospheric Rotary Table Configuration

FIG. 5 is a schematic plan view of one aspect of the invention, a batchprocessing platform, hereinafter referred to as system 500, wherein arotary table with a linear horizontal motion transfers processingcassettes between two staging platforms and two batch processingstations.

An important component of the COO of a substrate processing platform isdowntime related to planned and unplanned maintenance. Hence, aprocessing platform may have a relatively high nominal throughput, i.e.,substrates processed per hour, but if it suffers from substantiallyhigher downtime compared to other systems, it may effectively have along-term throughput, i.e., substrates processed per month, that is muchlower than other systems. To that end, having fewer robots that performless complex motions is a beneficial feature of a processing platform.The configuration illustrated in FIG. 5 has this feature.

System 500 includes two batch processing stations, 501A, 501B, anatmospheric transfer region 502, two staging platforms 503A, 503B, asingle transfer robot 504, a processing fluid delivery system, and arotary table 505A adapted to transfer processing cassettes rotationallyand with a linear horizontal motion. The atmospheric transfer region 502is similar in organization and operation to FI 102, described above inconjunction with FIG. 1C, and contains transfer robot 504, one or moreload stations 104A-B, and an environmental control assembly (not shownfor clarity). Batch processing stations, 501A, 501B are similar inorganization and operation to batch processing stations 101A, 101B,described above in conjunction with FIGS. 1A, 1B. An importantdifference is that staging platforms 503A, 503B are not positionedadjacent batch processing stations 501A, 501B, respectively. In stead,processing cassettes are transferred between staging platforms 503A,503B and the buffer chambers contained in batch processing stations501A, 501B. The processing cassettes are loaded horizontally into bufferchamber via a horizontal motion radially by rotary table 505A. Transferrobot 504 is substantially the same single track-mounted robot astransfer robot 220, described above in conjunction with FIGS. 2A-D.Transfer robot 504 may be stationary, however, reducing the cost andcomplexity of transfer robot 504 as well as improving the reliabilitythereof. Due to the difference in substrate between a typical FOUP and aprocessing cassette, transfer robot is preferably equipped with onlysingle blade robot arms, which further reduces the complexity and costof transfer robot 504.

Other components of system 500 that are substantially the same inorganization and operation as the corresponding components of systems200 include facilities towers 130A, 130B, overhead rack 140, and theprocess fluid delivery system. As with systems 100, 200, a FOUP stockermay be positioned over load stations 104AB to provide local storage ofFOUP's or other substrate transport pods during batch processing ofsubstrates.

In operation, processing cassettes located on staging platforms 503A,503B may be loaded with unprocessed substrates by transfer robot 504.Staging platforms 503A, 503B may further serve as cooling stations forfreshly processed substrates. Rotary table 505A is adapted to remove aprocessing cassette loaded with unprocessed substrates using ahorizontal actuator and a small Z-motion. Rotary table 505A then rotatesas necessary to position the processing cassette of unprocessedsubstrates adjacent an idle batch processing station. After processing,rotary table 505A returns cassettes to staging platforms 503A, 503B forcooling, unloading, and reloading with unprocessed substrates.

In a preferred sequence, substrate cooling and loading/unloadingoperations are performed while batch processing stations 501A, 501B areprocessing substrates. A first processing cassette is positioned on astaging platform, for example staging platform 503A, and loaded withsubstrates while a batch processing station, for example batchprocessing station 501A, is processing substrates in a second processingcassette. Prior to the completion of processing in batch processingstation 501A, rotary table 505A removes the first processing cassettefrom staging platform 503A. Once processing is completed on the secondprocessing cassette, rotary table 505A removes the second processingcassette from batch processing station 501A, rotates 180°, and placesthe first processing cassette into batch processing station 501A. Rotarytable 505A then positions the second processing cassette on an availablestaging platform 503A, 503B for cooling and subsequent unloading. Inthis way, batch processing station 501A is only idle for a matter ofseconds, i.e. the time necessary for rotary table 505A to remove acassette, rotate 180°, and position a second cassette in a batchprocessing station. In addition, the configuration illustrated in FIG. 5has fewer and/or simpler robots than other configurations of batchprocessing platform.

In one configuration, staging platforms 503A, 503B are capable ofsufficient vertical motion to accommodate the transfer of substratesand/or processing cassettes thereon. This configuration furthersimplifies the design of rotary table 505A, increasing the reliabilitythereof.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A substrate processing apparatus, comprising: a substrate processingchamber; a buffer chamber positioned adjacent to the substrateprocessing chamber; a processing cassette that is adapted to support twoor more substrates at a first spacing, wherein the processing cassetteis transferable between the buffer chamber and the substrate processingchamber; a staging cassette that is adapted to support two or moresubstrates at the first spacing; and a transfer robot adapted totransfer a substrate between a substrate transport pod and the stagingcassette using a single substrate handling blade, and to transfersubstrates between the staging cassette and the processing cassetteusing multiple substrate handling blades.
 2. The apparatus of claim 1,further comprising a factory interface having: an atmospheric transferregion in which the staging cassette and the transfer robot aredisposed; a filtration unit that is adapted to provide filtered air tothe atmospheric transfer region; and at least one load station formounting the substrate transport pod adjacent the atmospheric transferregion, wherein the at least one load station is further adapted to openthe substrate transport pod so that the interior of the substratetransport pod is in fluid communication with the atmospheric transferregion, and wherein the substrate transport pod is adapted to containtwo or more substrates horizontally at a second spacing.
 3. Theapparatus of claim 1, wherein the transfer robot is further adapted toremain translationally stationary while transferring one or moresubstrates between the processing cassette and the staging cassette. 4.The apparatus of claim 1, further comprising: a second substrateprocessing chamber; a second buffer chamber positioned adjacent to thesecond substrate processing chamber; a second processing cassette thatis adapted to support two or more substrates at the first spacing,wherein the second processing cassette is transferable between thesecond buffer chamber and the second substrate processing chamber; and asecond staging cassette that is adapted to support two or moresubstrates at the first spacing, wherein the transfer robot is furtheradapted to transfer substrates between the second staging cassette andthe second processing cassette using the multiple substrate handlingblades.
 5. The apparatus of claim 4, wherein the transfer robot isfurther adapted to transfer substrates between the first processingcassette and the second staging cassette using the multiple substratehandling blades.
 6. The apparatus of claim 1, wherein the multiplesubstrate handling blades are fixed-pitch substrate handling blades. 7.The apparatus of claim 1, further comprising: a fluid delivery systemthat is in fluid communication with an internal process volume of thesubstrate processing chamber, wherein the fluid delivery system isadapted to deliver a precursor-containing fluid to the internal processvolume so that a chemical vapor deposition (CVD) or an atomic layerdeposition (ALD) process can be performed on one or more substratespositioned therein; and a facilities tower proximate the substrateprocessing chamber, wherein the facilities tower containsprecursor-containing ampoules, and wherein the fluid delivery systemfluidly couples the facilities tower to the substrate processing chamberby means of an overhead rack.
 8. The apparatus of claim 1, furthercomprising: a vertical lift mechanism adapted to transfer a processingcassette into and out of the substrate processing chamber.
 9. Theapparatus of claim 1, wherein the transfer robot has: a two-bar linkagearm; and a motion assembly that is adapted to position the two-barlinkage arm along a linear path, wherein the linear path containslocations proximate the at least one load station and the substrateprocessing chamber.
 10. The apparatus of claim 1, further comprising: asecond substrate processing chamber; and a service aisle that isdisposed between the first and the second substrate processing chambersand is adapted to provide all necessary service access to the transferrobot and the first and second processing chambers.
 11. The apparatus ofclaim 10, further comprising: a first load station and a second loadstation, wherein the first load station is proximate the first substrateprocessing chamber and the second load station is proximate the secondsubstrate processing chamber.
 12. The apparatus of claim 11, furthercomprising: a second transfer robot disposed in the atmospheric transferregion proximate the second load station and the second substrateprocessing chamber and adapted to transfer a substrate between thesecond load station and the second substrate processing chamber, whereinthe second transfer robot has at least one substrate transfer arm thatcomprises multiple substrate handling blades, and wherein the firsttransfer robot is proximate the first load station and the firstsubstrate processing chamber.
 13. A substrate processing apparatus,comprising: a substrate processing chamber; a processing cassette thatis adapted to support two or more substrates; a cassette handler robotadapted to transfer the processing cassette between a staging platformand the substrate processing chamber; a substrate transfer robot that isadapted to transfer substrates between a substrate transport pod and theprocessing cassette; a buffer chamber having one or more walls that forman internal volume, wherein the internal volume is positioned below thesubstrate processing chamber; and a cassette transfer region in whichthe staging platform is disposed that is generally maintained atatmospheric pressure.
 14. The apparatus of claim 13, wherein thecassette handler robot is a linear translator and wherein the lineartranslator is adapted to contain a lift mechanism.
 15. The apparatus ofclaim 13, wherein the cassette handler robot is a rotary table.
 16. Theapparatus of claim 15, wherein the first processing cassette is on astaging platform and the rotary table is adapted to: receive a secondprocessing cassette from a lift mechanism; rotatably swap the positionsof the first processing cassette and the second processing cassette; andposition the first processing cassette to enable transferal of the firstprocessing cassette between the substrate processing chamber and thecassette transfer region by use of the lift mechanism.
 17. The apparatusof claim 16, wherein the staging platform is on the rotary table. 18.The apparatus of claim 17, wherein the rotary table is contained in theinternal volume.
 19. The apparatus of claim 18, wherein the rotary tableis adapted to horizontally translate the first processing cassette andthe second processing cassette.
 20. The apparatus of claim 13, furthercomprising a factory interface having: an atmospheric transfer region inwhich the staging cassette and the transfer robot are disposed; afiltration unit that is adapted to provide filtered air to theatmospheric transfer region; and at least one load station for mountingthe substrate transport pod adjacent the atmospheric transfer region,wherein the at least one load station is further adapted to open thesubstrate transport pod so that the interior of the substrate transportpod is in fluid communication with the atmospheric transfer region, andwherein the substrate transport pod is adapted to contain two or moresubstrates horizontally at a second spacing.